Three letters — F1 — sell a lot of seeds. Another three — IBL — decide what a breeding house is remembered for. Both describe how a cannabis line was bred, but they answer very different questions. If you collect genetics for provenance rather than novelty, that difference is everything.
What an F1 hybrid actually is
An F1 is the first filial generation: the direct cross of two distinct, stable parents. F1 plants often show hybrid vigour and a striking uniformity within that single generation. But an F1 is not fixed. Save its seeds, grow them out, and the next generation (F2) scatters — a lottery of phenotypes as the parental traits recombine. An F1 is a snapshot, not a lineage.
What an IBL gives you
An IBL, or inbred line, is a population bred across many generations until it breeds true. Its defining traits — structure, resin profile, terpene expression, flowering behaviour — reappear reliably from one generation to the next. Where an F1 impresses once, an IBL keeps its promise. That stability is the product of years of selection, not a marketing label.
Why collectors keep IBLs, not F1s
Collectors think in decades. An IBL is a stable reference point — a genetic identity you can return to, document, and preserve. Our own mother plants have been stabilised since 1994, across roughly thirty years of selection. That is why the pieces in our heritage collection are IBLs: they carry a documented, repeatable identity rather than a one-time result.
A quick way to tell them apart
- F1: uniform in one generation, unpredictable after. Bred for immediate expression.
- IBL: uniform generation after generation. Bred for permanence and provenance.
Neither is inherently superior — they serve different intentions. But if your goal is to hold a lineage rather than a moment, the IBL is the one worth keeping. See how our lines connect in the lineage map, or browse the catalogue to find which genetics are stabilised inbred lines.